FEA of RC slab based on the nonlinear material model and the effective moment of inertia

Abstract

The nonlinear elastic orthotropic model and a pseudo-nonlinear model that can perform finite element analysis of the slab, which is one of the important elements of reinforced concrete structures are suggested. The two models used the Mindlin plate theory and the 8-node element method for accurate analysis. The nonlinear elastic orthotropic model was based on the layer model and the concrete biaxial strength relationship. Additionally, the error value was reduced through the load iteration loop among the two loops during the analysis process. The pseudo-nonlinear model was based on a nonlayered model and the effective moment of inertia was based on the biaxial bending moment relationship. This model only has a loop for load increase, which reduces the accuracy of the values but can be expected to have low computational cost. In addition, the introduction of the modification factor has improved accuracy, but additional research on the factor is required. Based on these two models, the accuracy was checked by the moment-curvature behavior or load-displacement behavior of the three slabs.